public class Example4_5 {
	public static void main(String args[]) {
	   Rect ractangle = new Rect();
	   ractangle.width = 109.87;
	   ractangle.height = 25.18;
	   double area=ractangle.getArea();
	   System.out.println("矩形的面积:"+area);
	   Lader lader = new Lader ();
	   lader.above = 10.798;
	   lader.bottom = 156.65;
	   lader.height = 18.12;
	   area =lader.getArea();
	   System.out.println("梯形的面积:"+area);
	}
}